Insufflation stabilization system

ABSTRACT

Pressure conditioning systems for supplying insufflation gas to an open-ended body conduit such as a rectal cavity during a transanal minimally invasive surgery (TAMIS) procedure can reduce billowing of walls of the body conduit. A pressure conditioning system can include a pressure storage component, an accumulator, and a flow restrictor. The pressure storage component can include a variable volume reservoir that is biased to a relatively low volume state. The flow restrictor can include insufflation tubing with a restrictor plate having a relatively low diameter orifice. The pressure storage component, accumulator, and flow restrictor can be fluidly connected in various orders in series or as side branches from a gas flow conduit. Despite a pulsed or otherwise discontinuous insufflation gas flow and leakage and absorption from the body conduit, the pressure conditioning system can maintain a constant pressure within the body conduit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/282,781 entitled “INSUFFLATION STABILIZATION SYSTEM,” filed on Sep.30, 2016, currently pending, which claims the benefit of U.S.Provisional Patent Application Ser. No. 62/327,941, entitled“INSUFFLATION STABILIZATION SYSTEM,” filed Apr. 26, 2016; and U.S.Provisional Patent Application Ser. No. 62/235,128, entitled“INSUFFLATION STABILIZATION SYSTEM,” filed Sep. 30, 2015. Theabove-referenced applications are each incorporated by reference hereinin their entireties.

BACKGROUND OF THE INVENTION Field of the Invention

The present application relates to pressure conditioning apparatuses forsurgical insufflation systems and more particularly to pressureconditioning apparatuses to maintain a substantially constant pressureat a surgical site despite pulsing or discontinuous insufflation supplyand leakage and absorption at the surgical site.

Description of the Related Art

During Trans Anal Minimally Invasive Surgery (TAMIS) an insufflationmachine is used to inflate the rectum with an insufflation gas such ascarbon dioxide (CO₂). The inflation allows room for a surgeon to performa surgical procedure using laparoscopic instruments and techniques. Manyinsufflation machines provide CO₂ in pulses, alternating pressurizationpulses with pressure measurements. The colorectal system, however, isnot a sealed volume and CO₂ continuously leaks from the inflatedsurgical area causing the pressure to drop. Additionally, CO₂ is readilyabsorbed by the walls of the colorectal system thereby exacerbating theloss of pressure caused by the leakage. CO₂ can leak from the systemthrough a variety of leak paths, ranging from the length of thecolorectal system, absorption by the intestine/colorectal walls, andthrough the surgical instruments and tools used to gain access. At somepoints of the procedure, a smoke evacuation port is constantly open inorder to encourage the flow of CO₂, forcing out smoke generated byelectrocautery. The multitude of leak paths leads to a loss of pressureand pulsed insufflation flow manifests itself as billowing of the rectalwalls. The billowing follows the pressure cycle from the insufflationmachine: when the machine is providing CO₂ pressure the rectal wallsexpand and when the insufflation machine is not supplying pressure(measuring the pressure) the rectal walls contract. The movement of therectal walls can make laparoscopic surgery more difficult during aTAMIS, or other transanal procedure, which can require manipulation ofand treatment of growths on the rectal walls.

SUMMARY OF THE INVENTION

In various embodiments, the apparatuses described herein cansignificantly reduce tissue billowing of an open-ended body conduit suchas a rectal cavity that is insufflated by a pulsing insufflation pump.The apparatuses can condition a pulsed or discontinuous insufflation gasflow to provide a substantially continuous insufflation gas flow thatcan have a flow rate that varies responsive to pressure losses at aninlet from a zero pressure differential state between pulses of aninsufflation pump and backpressure reduction at an outlet due to leakageand absorption by tissue at a surgical site in an open-ended bodyconduit. Moreover, the apparatuses can absorb energy from a relativelyhigh flow output from an insufflator and provide a lower, but morecontinuous flow to the surgical field.

In certain embodiments, a gas flow pressure conditioning apparatus foruse with a pulsing insufflation pump is provided. The apparatuscomprises an inlet fluid port, an outlet fluid conduit, and a reservoir.The inlet fluid port is configured to receive a flow of gas from thepulsing insufflation pump. The outlet fluid conduit is configured toprovide a flow of insufflation gas to a surgical site. The reservoir isfluidly coupled to the inlet fluid conduit and the outlet fluid conduit.The inlet fluid port has a first inner diameter and the outlet fluidconduit has a second inner diameter larger than the first innerdiameter.

In certain embodiments, an insufflation system is provided. Theinsufflation system comprises a surgical access port and a gas flowpressure conditioning apparatus for use with a pulsing insufflationpump. The surgical site access port comprises a port surface, a firsttrocar, and a second trocar. The first trocar is positionable throughthe port surface. The first trocar has a first instrument channelextending therethrough. The second trocar is positionable through theport surface. The second trocar has a second instrument channelextending therethrough and an insufflation port. The gas flow pressureconditioning apparatus comprises an inlet fluid conduit, an outlet fluidconduit, and a reservoir. The inlet fluid conduit is configured toreceive a flow of gas from the pulsing insufflation pump. The outletfluid conduit is configured to provide a flow of insufflation gas to thesurgical site access port. The reservoir is fluidly coupled to the inletfluid conduit and the outlet fluid conduit. The inlet fluid conduit hasa first inner diameter and the outlet fluid conduit has a second innerdiameter larger than the first inner diameter.

In certain embodiments, a gas flow pressure conditioning apparatus foruse with a pulsing insufflation pump is provided herein. The apparatuscomprises an inlet port, an accumulator, a pressure storage vessel, andan outlet port. The inlet port is configured to receive a flow of gasfrom the pulsing insufflation pump. The accumulator fluidly is coupledto the inlet port. The pressure storage vessel is fluidly coupled to theinlet port. The flow restrictor is fluidly coupled to the inlet port.The outlet port is fluidly coupled to the inlet port and disposeddownstream of the accumulator, the pressure storage vessel, and the flowrestrictor.

In certain embodiments, an insufflation system for maintainingsubstantially constant pressure at a surgical site is provided herein.The insufflation system comprises a pulsing insufflation pump, and apressure conditioning apparatus. The insufflation pump has a pumpoutlet. The pressure conditioning apparatus comprises an inlet, apressure storage container, a reservoir, a flow restrictor, and anoutlet port.

In certain embodiments, a surgical site sealing apparatus for sealing anopen ended body conduit is provided herein. The sealing apparatuscomprises an elastomeric bag. The elastomeric bag has an open end and aclosed end opposite the open end. The elastomeric bag is sized andconfigured to be positioned within a body conduit. The elastomeric baghas an insertion configuration in which the bag is advanceable withinthe body conduit in an undisturbed state. The elastomeric bag isinflatable to an insufflated condition in which the elastomeric bagdistends the body conduit.

In certain embodiments, a surgical site sealing apparatus for sealing anopen ended body conduit is provided herein. The sealing apparatuscomprises an inflatable member and an inflation tube. The inflatablemember has a deflated state sized to be advanced through an open end ofthe body conduit. The inflatable member is inflatable by fluid to aninflated state sized to sealingly engage with walls of the body conduit.The inflation tube extends from a proximal end to a distal end andhaving a lumen extending between the proximal end and the distal end,the distal end of the inflation tube coupled to the inflatable member,and the lumen fluidly coupled to the inflatable member to provide thefluid to the inflatable member.

In certain embodiments, a surgical site sealing apparatus for sealing anopen ended body conduit is provided herein. The sealing apparatuscomprises a diaphragm and a flexible ring. The flexible ring disposedaround the diaphragm, the flexible ring configurable in a firstconfiguration in which the flexible ring is advanceable through the bodyconduit and a second configuration in which the flexible ring issealingly engageable with a wall of the body conduit.

In certain embodiments, an insufflation system for maintainingsubstantially constant pressure at a surgical site is provided. Theinsufflation system comprises a reservoir. The reservoir comprises aninsufflation chamber, a pressurization chamber, and a separation member.The insufflation chamber comprises an inlet port fluidly couplable to aninsufflation pump and an outlet port. The pressurization chambercomprises a pressurization port couplable to a source of pressurizedfluid and a pressure relief valve. The separation member fluidlyisolates the insufflation chamber from the pressurization chamber. Theseparation member is movable responsive to an insufflation pressure inthe insufflation chamber and a pressurization pressure in thepressurization chamber.

In certain embodiments, an insufflation system for maintainingsubstantially constant pressure at a surgical site is provided. Theinsufflation system comprises a reservoir and a pressure control system.The reservoir comprises an insufflation chamber and a piston. Theinsufflation chamber comprises an inlet port fluidly couplable to aninsufflation pump and an outlet port. The piston is slidable within thereservoir to define a volume of the insufflation chamber. The pressurecontrol system comprises a flow sensor fluidly coupled to the inletport, a pressure sensor fluidly coupled to the outlet port, a linearactuator, and a programmable logic controller. The linear actuator isoperably coupled to the piston. The linear actuator has a positionfeedback sensor. The programmable logic controller is electricallycoupled to the flow sensor, the pressure sensor, the linear actuator,and the position feedback sensor. The logic controller is configured toactuate the linear actuator to position the piston in a position withinthe reservoir to maintain a desired pressure at the outlet portresponsive to electrical signals from the flow sensor and the pressuresensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an embodiment of gas flow pressure conditioningapparatus;

FIG. 2 is a schematic view of the embodiment of pressure conditioningapparatus of FIG. 1 for use in a surgical site access system;

FIG. 3 is a schematic view of an embodiment of surgical site accesssystem including the pressure conditioning apparatus of FIG. 1;

FIG. 3A is a schematic view of another embodiment of pressureconditioning apparatus for a surgical site access system;

FIG. 4 is a perspective view of the pressure conditioning apparatus ofFIG. 1 in an expanded configuration on a test fixture with a simulatedbody conduit;

FIG. 5 is a side view of another embodiment of gas flow pressureconditioning apparatus;

FIG. 6 is a side view of another embodiment of gas flow pressureconditioning apparatus;

FIG. 7 is a perspective view of an embodiment of gas flow pressureconditioning apparatus;

FIG. 8 is a front view of the pressure conditioning apparatus of FIG. 7;

FIG. 9 is a side view of the pressure conditioning apparatus of FIG. 7;

FIG. 10 is a side view of another embodiment of gas flow pressureconditioning apparatus on a test fixture;

FIG. 11 is a schematic view of the gas flow pressure conditioningapparatus of FIG. 10;

FIG. 12 is a side view of another embodiment of gas flow pressureconditioning apparatus on a test fixture;

FIG. 13 is a side view of another embodiment of gas flow pressureconditioning apparatus on a test fixture;

FIG. 14 is a perspective view of one embodiment of a pressure storagecomponent for a pressure conditioning apparatus;

FIG. 15 is a perspective view of another embodiment of pressure storagecomponent for a pressure conditioning apparatus;

FIG. 16 is a perspective view of another embodiment of pressure storagecomponent for a pressure conditioning apparatus;

FIG. 17 is a side view of another embodiment of gas flow pressureconditioning apparatus on a test fixture;

FIG. 18A is a schematic view of one embodiment of insufflation system;

FIG. 18B is a schematic view of another embodiment of insufflationsystem having a flow restricting orifice;

FIG. 18C is a schematic view of another embodiment of insufflationsystem having a side branch attenuator;

FIG. 18D is a schematic view of another embodiment of insufflationsystem having a Helmholtz resonator;

FIG. 19A is a schematic view of one embodiment of a surgicalinsufflation system including a gas flow pressure conditioningapparatus;

FIG. 19B is a schematic view of another embodiment of a surgicalinsufflation system including a gas flow pressure conditioningapparatus;

FIG. 19C is a schematic view of another embodiment of a surgicalinsufflation system including a gas flow pressure conditioningapparatus;

FIG. 19D is a schematic view of another embodiment of a surgicalinsufflation system including a gas flow pressure conditioningapparatus;

FIG. 19E is a schematic view of another embodiment of a surgicalinsufflation system including a gas flow pressure conditioningapparatus;

FIG. 19F is a schematic view of another embodiment of a surgicalinsufflation system including a gas flow pressure conditioningapparatus;

FIG. 20 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump;

FIG. 21 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump andan embodiment of pressure conditioning apparatus;

FIG. 22 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump andanother embodiment of pressure conditioning apparatus;

FIG. 23 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump andanother embodiment of pressure conditioning apparatus;

FIG. 24 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump andanother embodiment of pressure conditioning apparatus;

FIG. 25 is a graph of surgical site pressure over time for a simulatedsurgical access site in a cadaver laboratory setting insufflated with apulsatile insufflation pump;

FIG. 26 is a graph of surgical site pressure over time for a simulatedsurgical access site of FIG. 25 insufflated with a pulsatileinsufflation pump and an embodiment of pressure conditioning apparatus;

FIG. 27 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump andan embodiment of pressure conditioning apparatus;

FIG. 28 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump andanother embodiment of pressure conditioning apparatus;

FIG. 29 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump andanother embodiment of pressure conditioning apparatus;

FIG. 30 is a graph of surgical site pressure over time for a simulatedsurgical access site insufflated with a pulsatile insufflation pump andanother embodiment of pressure conditioning apparatus;

FIG. 31 is a schematic view of an embodiment of insufflation system;

FIG. 32 is a schematic view of another embodiment of insufflationsystem;

FIG. 33 is a schematic view of another embodiment of insufflationsystem;

FIG. 34A is a perspective view of an embodiment of body conduit sealingdevice;

FIG. 34B is a perspective view of another embodiment of body conduitsealing device; and

FIG. 34C is a perspective view of another embodiment of body conduitsealing device.

DETAILED DESCRIPTION OF THE INVENTION

In various embodiments, a gas insufflation pressure conditioningapparatus can be fluidly coupled to a pulsing insufflation machine toalleviate billowing of a body conduit and reduce or eliminate themovement of the rectum walls when using the pulsing insufflation machinein a TAMIS procedure. The pressure conditioning apparatus can beconfigured to maintain a substantially constant pressure and flow in thebody conduit despite leakage and absorption from the body conduit at thesurgical site and a pulsing insufflation gas flow profile. Additionally,billowing can be further alleviated through provision of a body conduitsealing or closure device to create a closed volume within the rectalcavity to minimize the pressure lost while eliminating the movement ofthe rectum walls.

With reference to FIGS. 1-4 an embodiment of insufflation gas pressureconditioning apparatus 70 is illustrated. In the illustrated embodiment,the pressure conditioning apparatus 70 comprises a gas flow pathextending from a segment of inlet gas tubing 92 through an elastomericfilm pouch to a segment of outlet gas tubing 94. Advantageously, theelastomeric film pouch provides pressure conditioning functions ofpressure storage, insufflation gas volume accumulation, and flowrestriction to maintain a substantially consistent insufflation gas flowat a surgical site despite a discontinuous, pulsatile flow from aninsufflator.

With reference to FIG. 1, the film pouch 86 can be formed of a sheet ofpolymeric film that is folded upon itself and welded to seal edges 88and create an enclosed volume. In the illustrated embodiment, with thepouch 86 in a deflated condition, the pouch has a generally rectangularshape with relatively long width and a relatively shorter height. It iscontemplated that in other embodiments, the pouch can be formed in othershapes to achieve desired product packaging, aesthetic, or gas flowconsiderations.

With continued reference to FIG. 1, an inlet port 82 and an outlet port84 can be added to the film pouch 86 to create a gas flow path throughthe pouch. In the illustrated embodiment, the inlet port 82 and outletport 84 are positioned on opposite sides of the pouch 86 to provide arelatively direct flow path along a longitudinal axis of the width ofthe pouch 86. In other embodiments, it is contemplated that otherpositions of the inlet port 84 and outlet port 86 can be used to varythe gas flow characteristics of the pressure conditioning apparatus. Forexample, in some embodiments, the inlet port 82 and outlet port 84 canbe positioned adjacent one another along one edge or can be positionedon opposite edges with respect to the height of the pouch 86 such thatthe pressure conditioning apparatus can have attributes of a side branchattenuator (schematically illustrated in FIG. 18C).

In the illustrated embodiment, the inlet port 82 and outlet port 84 caneach comprise a bag port having a barbed fitting, such as arecommercially available from Value Plastics, Inc. The pressureconditioning apparatus can further comprise a segment of inlet tubing 92coupled to the barbed fitting of the inlet port 82 and a segment ofoutlet tubing 94 coupled to the barbed fitting of the outlet port 84. Insome embodiments, the outlet port 84 can be coupled directly toinsufflation tubing. In other embodiments, the outlet port 84 and outlettubing 94 can be formed as a single component. The inlet tubing 92 canhave a fitting end configured to be coupled to an insufflator or toinsufflation tubing from an insufflator. The outlet tubing 94 can have afitting end configured to be coupled to insufflation tubing fluidlycoupled to a surgical access port.

While the illustrated embodiment includes both an inlet tubing 92 and anoutlet tubing 94, in certain embodiments, it can be desirable that thepressure conditioning apparatus can include only a single length oftubing, or can be provided solely with ports. For example, in certainembodiments, a pressure conditioning apparatus can include an inlet port82 at an upstream end and an outlet tubing 94 at a downstream end. Thusa desired length of inlet tubing can be associated with an insufflator.In other embodiments, a pressure conditioning apparatus can include aninlet port 82 at an upstream end and an outlet port 84 at a downstreamend such that inlet and outlet tubing can be associated with aninsufflator and a surgical access port. Moreover, in some embodiments,one or both of the inlet and outlet ports can include a luer fittingrather than a barbed fitting such that at least one of the inlet portand the outlet port comprises a luer port. In some embodiments, at leastone of the inlet port and the outlet port can be heat sealed to thepouch. FIG. 3A illustrates an embodiment of pressure conditioningapparatus 70 having a film pouch 86 with an inlet port 82′ having a luerfitting, and an outlet port 84′ coupled to a length of outlet tubing 94′that is coupled to an insufflation trocar 940. In the illustratedembodiment, the outlet tubing 94′ is a segment of corrugated tubing,which can be desirable in insufflation systems to reduce kinking of thetubing and the potential for related fluid flow disruptions.

The pouch 86 can be sized and configured to provide pressureconditioning aspects of a separate pressure storage component andaccumulator of other embodiments of pressure conditioning devicesherein. For example, in some embodiments, the pouch can be formed of apolymeric material having predetermined thickness and elasticityproperties to provide the desired pressure storage. In some embodiments,the pouch 86 can be formed of a polyurethane film that can expand andcontract responsive to insufflation pressure. It is contemplated that inother embodiments, other film materials and/or thicknesses can be usedin a pressure conditioning apparatus to achieve the desired pressurestorage.

The pouch 86 can be sized to stabilize the volume of an open-ended bodyconduit at a surgical site location supplied with pulsed insufflation.As further described with respect to FIGS. 2, 3, and 20-30, in someembodiments, a pouch 86 can be sized to provide a desired pressureconditioning profile for a TAMIS procedure. Desirably, in certainembodiments, the pouch 86 can have a volume of at least approximately6.5 liters. In other embodiments, the pouch 86 can have a volume ofbetween approximately 6.5 and approximately 8 liters. In one embodiment,the pouch 86 can have a volume of approximately 7.4 liters. Where thepouch has a pouch volume that is undesirably small for the surgicalsite, there can be insufficient pressure storage and accumulated volumeto condition pulse cycles of an insufflation pump. Where the pouch isundesirably large for the surgical site, there can be an insufflationlag time as pulse cycles of the insufflator can be influenced bypressure fluctuations of the relatively large pouch volume rather thanthe surgical site. It is contemplated that the pouch can be configuredwith a different pouch volume than the range discussed above for use inpatients having particularly small or particularly large colorectalvolume. Likewise, it is contemplated that the pouch can have a differentpouch volume if it is desired to use the pressure conditioning apparatus70 to condition insufflation pressure pulses at a different surgicalsite.

With reference to FIG. 2, the pressure conditioning apparatus of FIG. 1is schematically illustrated. The pressure conditioning apparatus 70comprises an elastomeric film pouch 86 or bag that can have an inletport 82 and an outlet port 84 that create a gas flow path through thepouch. The pressure conditioning apparatus can further comprise an inletfluid conduit such as a length of inlet gas tubing 92 and an outletfluid conduit such as a length of outlet gas tubing 94. The inlet gastubing 92 can include a fitting or coupling to be fluidly coupled to aninsufflation pump.

With continued reference to FIG. 2, in some embodiments the inlet gastubing 92 and outlet gas tubing 94 can be sized relative to one anotherto provide a desired pressure conditioning profile. For example, in theillustrated embodiments, the inlet tubing 92 can have a first innerdiameter and the outlet tubing 94 can have a second inner diameterlarger than the first inner diameter.

With reference to FIGS. 2-3 in some embodiments, a pressure conditioningapparatus 70 as described herein can be included in a surgical siteaccess system 900 such as a surgical access port 902 having a portsurface 904 such as an artificial body wall defined by a gel surface ofa surgical access port sold under the trademarks GELPORT and GELPOINT.In certain embodiments, the pressure conditioning apparatus 70 asdescribed herein can be included in a surgical site access systemconfigured for application in a natural orifice entry site surgicalprocedure such as a TAMIS procedure such as a surgical access port soldas a GELPOINT path system. Certain aspects of the GELPOINT path systemare described in U.S. Pat. Nos. 9,289,115 and 9,289,200, each issuedMar. 22, 2016, each entitled “NATURAL ORIFICE SURGERY SYSTEM,” each ofwhich are incorporated herein by reference in their entireties. Ingeneral, the surgical site access system 900 can comprise a pressureconditioning apparatus 70, a surgical access port 902 having a portsurface 904, and a plurality of trocars 930, 940 configured to beadvanced through the port surface 904 and to sealingly engage surgicalinstruments inserted therethrough.

With continued reference to FIG. 3, in some embodiments, the surgicalaccess port 902 can comprise at least one insufflation port 910, 920. Insome embodiments of surgical site access system 900, the pressureconditioning apparatus 70 can be fluidly coupled to one of theinsufflation ports 910, 920. The other of the insufflation ports 910,920 can then either be left free and remain closed with a stopcock valveor other closure device, be coupled to another source of gas, or beselectively opened to provide smoke evacuation for electrosurgicalprocedures.

With continued reference to FIG. 3, in some embodiments, the surgicalsite access system 900 can further comprise an insufflation trocar 940.The pressure conditioning apparatus 70 can be fluidly coupled to theinsufflation trocar 940 and the trocar 940 advanced through theartificial body 904 wall to provide insufflation gas flow to thesurgical site. The insufflation trocar 940 can comprise an instrumentaccess channel 942 and an insufflation port 944. In certain embodiments,the insufflation port 944 of the insufflation trocar 940 can have arelatively large diameter relative to the insufflation ports 910, 920 ofthe surgical access port 902. In some embodiments, the insufflation port944 of the insufflation trocar 940 can comprise a barbed fitting toreceive the outlet gas tubing 94 of the pressure conditioning apparatus70. Accordingly, the insufflation trocar 940 can desirably accommodateinsufflation gas flow rates of a fluid coupling such as outlet tubing 94of a pressure conditioning apparatus 70 having a relatively large innerdiameter, such as the embodiment of FIG. 2.

The pressure conditioning apparatus 70 can be sized and configured toprovide a desirable pressure conditioning profile for a surgical site atan open body conduit. For example, it can be desirable for the pressureconditioning apparatus to provide an insufflation gas flow having arelatively small lag time, and a relatively small pressure deviation.The lag time represents a time delay between activation of aninsufflation pump fluidly coupled to the surgical site access system andreaching a desired insufflation pressure at the surgical site. Thepressure deviation represents a pressure difference between a highpressure peak and a low pressure peak if insufflation pressure at thesurgical site is plotted over time. Moreover, it can be desirable thatthe pressure conditioning apparatus be relatively compact such that itdoes not require a significant amount of operating room space.

With reference to FIG. 4, the insufflation gas pressure conditioningapparatus 70 of FIG. 1 is illustrated coupled to a test fixtureincluding a distended simulated body conduit 180. The pressureconditioning apparatus 70 is illustrated with the pouch 86 in aninflated condition and a gas flow path (arrows showing flow direction)indicated from the inlet tube segment 92, through the pouch 86, throughthe outlet tube segment 94 and to the simulated body conduit 180.Desirably, a simulated body conduit 180, can be used to assess theconditioned pressure profile performance of various pressureconditioning apparatus 70 film pouch materials, thicknesses, volumes,and geometries as further discussed with reference to FIGS. 20-30.

With reference to FIG. 5, another embodiment of pressure conditioningapparatus 70 is illustrated. In the illustrated embodiment, a filmpouch, such as that of FIGS. 1-4 can be positioned within an outerenvelope 71. The outer envelope 71 can be sized to allow a predeterminedamount of elastic and/or plastic deformation of the film pouch of thepressure conditioning apparatus 70 while preventing the film pouch andits associated seams from plastically deforming to a material yield orsplit-seam condition. Thus, insufflation gas flows from an inlet tubesegment 92, through the pressure conditioning apparatus 70 through theoutlet tube segment 94. As the pressure conditioning apparatus 70inflates and expands, it can abut an inner surface of the outer envelope71, which reduces or stops further expansion.

In some embodiments, the outer envelope 71 can comprise the same filmmaterial and thickness as the film pouch of the pressure conditioningapparatus 70. In other embodiments, it can be desirable that the outerenvelope is formed of a different polymeric film material or a differentthickness of the same material. For example, in some embodiments, thefilm pouch can be formed of a polyurethane film having a thickness of0.003 inches and the outer pressure envelope can be formed of apolyurethane film having a thickness of 0.006 inches.

With reference to FIG. 6, another embodiment of pressure conditioningapparatus 70 is illustrated. In the illustrated embodiment, a film pouchof the pressure conditioning apparatus is positioned within an outersleeve 73. The outer pressure sleeve can have a generally tubularprofile with open ends, through which the film pouch of the pressureconditioning apparatus 70 extends. As with the embodiment of FIG. 5, theouter pressure sleeve can allow a predetermined amount of elastic andplastic deformation of the pressure conditioning apparatus 70 whilelimiting the plastic deformation to prevent material yield or seamsplitting when pressurized with an insufflation gas flow. The outersleeve 73 can be joined to the film pouch of the pressure conditioningapparatus 70 such as by being heat welded along a seam of the filmpouch. In the illustrated embodiment, the outer sleeve 73 is joined tothe film pouch along one seam of the film pouch. In other embodiments,the outer sleeve can be joined at more than one seam of the film pouchor can be joined at other locations of the film pouch with a welded seamor with adhesives.

With reference to FIGS. 7-9, perspective, front, and side views ofanother embodiment of gas flow pressure conditioning apparatus 10 areillustrated. In the embodiment of FIG. 7-9 the various pressureconditioning functions of pressure storage, volume accumulation, andflow rate restriction can each be provided by a dedicated component. Inthe illustrated embodiment, the pressure conditioning apparatus 10includes a housing 12 enclosing or substantially enclosing components ofthe apparatus 10. The housing 12 can be sized and configured to fit onan equipment cart or rack for use in a medical facility. A fluid flowinlet port 20 and outlet port 60 can protrude from or be recessed intothe housing 12. During a surgical procedure, the inlet port 20 can befluidly coupled to an insufflation source, such as a pulsinginsufflation pump. The pulsing insufflation pump can provide fluid flowin a non-continuous or pulsed stream. The outlet port 60 can be fluidlycoupled to a surgical access port such as an insufflation channel on atrocar cannula, a single site minimally invasive surgical access port,or a natural orifice or transanal minimally invasive surgery accessport.

With continued reference to FIGS. 7-9, in some embodiments, the housing12 of the pressure conditioning apparatus 10 encloses a pressure storagecomponent 30 and an accumulator 50. In some embodiments, the housing 12can comprise an internal wall that forms separate compartments for eachof the pressure storage component 30 and the accumulator 50. Thepressure storage component 30 and the accumulator 50 can be fluidlycoupled to one another and to the inlet port 20 and outlet port 60 tocreate a fluid flow path between the inlet port 20 and the outlet port60. For example, a segment of gas flow tubing 45 can fluidly couple thepressure storage component 30 to the accumulator 50. As furtherdescribed with respect to FIGS. 18A-18D, in some embodiments the segmentof gas flow tubing 45 can be fluidly coupled to a flow restrictor tofurther condition the gas flow therethrough. The flow restrictor can beconfigured to reduce the amplitude of pulses generated by aninsufflation machine while lengthening the duration of the pulses.Accordingly, the flow restrictor can condition a pulsed insufflation gasinflow to become closer to a continuous flow downstream of the flowrestrictor.

With continued reference to FIGS. 7-9, In the illustrated embodiment,the pressure storage component 30 is downstream of the inlet port 20,the gas flow tubing 45 is downstream of the pressure storage component,the accumulator 50 is downstream of the gas flow tubing 45, and theoutlet 60 is downstream of the accumulator 50. It is contemplated thatin other embodiments other arrangements of components can be used. Forexample, in some embodiments, a pressure conditioning apparatus 10 cancomprise an accumulator positioned upstream of a pressure storagecomponent and the pressure storage component positioned upstream of aflow restrictor relative to the fluid flow path. In other embodiments, apressure conditioning apparatus 10 can comprise a flow restrictorpositioned upstream of a pressure storage component and the pressurestorage component positioned upstream of an accumulator relative to thefluid flow path.

Furthermore, in the illustrated embodiment, the pressure storagecomponent 30, the gas flow tubing 45, and the accumulator 50 are fluidlycoupled in series between the inlet port 20 and the outlet port 60. Inother embodiments, it is contemplated that various arrangements ofparallel or side branch fluid couplings can be included with pressureconditioning apparatuses.

The pressure storage component is capable of receiving, storing andreturning pressurized insufflation gas such as CO₂ such that thereturned CO₂ is at substantially the same pressure as the received CO₂.Additionally, the pressure storage component can desirably be able toreturn pressurized CO₂ relatively quickly. For example, in someembodiments it is desirable that the pressure storage component isconfigured to maintain a pressure of an insufflation gas flow uponcessation of an insufflation pulse or relief of backpressure from thesurgical site in less than approximately 10% of the time that a pulsinginsufflation machine would be in a pressurize cycle. Advantageously, thepressure storage component 30 in conjunction with the pressureconditioning apparatus 10 can be configured to quickly vary the flowrate of insufflation gas at the outlet port 60 to counteract leakage andabsorption of CO₂ at the surgical site downstream of the outlet. Thus,the pressure conditioning apparatus 10 can maintain a substantiallyconstant pressure at the surgical site.

As illustrated, the pressure storage component 30 comprises a vessel 32or fluid reservoir and a pressure generating mechanism. The vessel 32can be a flexible or elastomeric container having a variable internalvolume defined by flexing or expansion of walls thereof between a first,relatively low volume state and a second, relatively high volume state.The pressure generating mechanism can bear on an outer wall of thevessel 32 to bias the vessel 32 towards the first, relatively low volumeconfiguration to maintain a desired pressure of gas within the vessel 32even when flow of gas at the inlet 20 is interrupted (e.g. betweenpressurized pulses from a pulsing insufflation pump) or backpressure isreduced from the outlet 60 (e.g. when insufflation gas escapes from asurgical site or is absorbed by tissue at the surgical site).

With continued reference to FIGS. 7-9, the pressure generating mechanismcan comprise a first plate 34 bearing against a wall of the vessel 32, asecond plate 36 bearing against the housing 12, and a biasing mechanismsuch as one or more coil springs 38 positioned between the first andsecond plates 34, 36 to generate a biasing force tending to separate theplates and compress the vessel 32. In the illustrated embodiment, theplates 34, 36 are generally rectangular and the biasing mechanismcomprises four coil springs 38, with a coil spring 38 extending betweenthe first and second plates 34, 36 adjacent each corresponding corner ofthe generally rectangular plates. In other embodiments, it iscontemplated that more or fewer than four coil springs 38 can bepositioned at various positions between the plates 34, 36.

The plates 34, 36 and the housing 12 can each comprise engagementsurfaces to align the plates in a desired orientation within the housingto generate the biasing force in a desired direction relative to thehousing 12 and the vessel 32. For example, in the illustratedembodiment, the plates 34, 36 each include a plurality of recesses orgrooves positioned to engage with and slide along inwardly-protrudingribs in the housing 12.

In some embodiments, the pressure storage component 30 can comprise apressure adjustment mechanism such as one or more threaded spacers 40that can allow a user to adjust a position of the second plate 36relative to the housing 12. Advancing the threaded spacers 40 toposition the second plate 36 relatively deeply within the housing canprovide a relatively high biasing force on the vessel 32 generated bythe pressure generating mechanism. Alternatively, retracting thethreaded spacers 40 to position the second plate 36 relatively close toan upper surface of the housing can provide a relatively low biasingforce on the vessel 32 generated by the pressure generating mechanism.In the illustrated embodiment, the threaded spacers 40 each comprise athreaded shaft having a proximal end with an adjustment knob thereon anda distal end positioned against the second plate 36. The threaded shaftsengage corresponding threaded apertures formed in the upper surface ofthe housing 12.

With continued reference to FIGS. 7-9, as the insufflation gas flowsdownstream from the pressure storage component 30, it passes through thegas flow tubing 45 with its flow restrictor to further condition apulsed profile of the insufflation gas flow and in to the accumulator50. The accumulator 50 can provide a reservoir of insufflation gas,pressurized by the pressure storage component 30, that can stabilize apressure at a surgical site fluidly coupled to the outlet port 60between pulses of the insufflation machine.

In certain embodiments, the accumulator 50 can comprise a flexible orrigid vessel or reservoir. The accumulator 50 can be sized with a volumethat can retain a predetermined percentage of a volumetric rating of theinsufflation pump such that the system maintains a substantiallyconstant pressure at the surgical site. For example, desirably, theaccumulator can have a volume that contains from approximately 10%-20%of the volumetric rating of the insufflation machine. Preferably, theaccumulator can have a volume that contains approximately 15% of thevolumetric rating of the insufflation machine.

With reference to FIG. 10, a side view of another embodiment ofinsufflation gas pressure conditioning apparatus 110 is illustrated. Inthe illustrated embodiment, the conditioning apparatus 110 comprises agas flow path extending from an inlet port 120 to an outlet port 160,with the outlet port 160 illustrated as being fluidly coupled to adistended simulated body conduit 180 on a test fixture. The inlet port110 is fluidly coupled to a gas conduit 170. The pressure conditioningapparatus 110 includes a pressure storage component 130, aflow-restricting gas tube 145, and an accumulator 150 fluidly coupled tothe gas conduit 170. The various components of the pressure conditioningapparatus 110 operate substantially as described above with respect tothe pressure conditioning apparatus of FIGS. 7-9.

With continued reference to FIG. 10, in the illustrated embodiment, thepressure storage component 130 comprises a vessel having a bellowsconfiguration. The bellows is expandable responsive to gas pressure, butis biased towards a relatively low volume, contracted configuration. Inthe illustrated embodiment, the accumulator 150 comprises a pouch havinga predetermined volume. The pouch can be formed of a film of a polymericmaterial, such as a polyurethane film. The pressure storage component130, gas tube 145, and accumulator 150 can be housed within a housing112 similar to that of the embodiment of FIGS. 7-9.

With reference to FIG. 11, a schematic view of the pressure conditioningapparatuses of FIGS. 10 and 12 is illustrated. As illustrated, thepressure storage component 130 extends from a side branch of the gasconduit 170 that extends from the inlet port 120 to the outlet port 160.Accordingly, in various embodiments of pressure conditioning apparatusdescribed herein, the components can be disposed in various flowarrangements including serial and side branch arrangements to maintain adesired pressure profile at a surgical site.

With reference to FIG. 12, a side view of another embodiment of gas flowpressure conditioning apparatus 210 is illustrated. The apparatus ofFIG. 12 is substantially similar to that of FIG. 10 with a housing 212containing a pressure storage component 230 and accumulator 250. A gasflow conduit 270 can fluidly couple the pressure storage component 230and accumulator 250 to an inlet port 220 and outlet port 260. In theillustrated embodiment, the housing 212 is sized to have a reducedheight footprint as compared with housing 112 of the embodiment of FIG.10. Accordingly, the materials, volumes, and biasing properties of thepressure storage component 230 and accumulator 250 can be selected tomaintain a desired insufflation pressure profile.

With reference to FIG. 13, a side view of another embodiment of gas flowpressure conditioning apparatus is illustrated. The apparatus of FIG. 13is substantially similar to that of FIGS. 10 and 12, however a pressurestorage component 330 and accumulator 350 are not positioned within ahousing. A gas flow conduit 370 can fluidly couple the bellows-profilepressure storage component 330 and accumulator 350 to an inlet port andoutlet port that is coupled to a simulated body conduit 180.

With reference to FIGS. 14-16, various embodiments of a pressure storagecomponent 430, 530, 630 are illustrated. In each of the illustratedembodiments, the pressure storage component 430, 530, 630 can comprise areservoir or vessel 432, 532, 632. The reservoir 432, 532, 632 can havea variable volume, and a pressure generating mechanism can bias thereservoir 432, 532, 632 to a relatively low volume state.

With reference to FIG. 14, the illustrated pressure storage component430 comprises a polymeric pouch reservoir 432 having a compressionsleeve 438 encircling a portion thereof. The compression sleeve 438comprises an elastic mesh that biases the reservoir 432 to a relativelylow volume configuration to store and return pressure from a port 420 ofthe pressure storage component 430.

With reference to FIG. 15, the illustrated pressure storage component530 can comprise a reservoir 532 that is sandwiched by compressionmembers or plates 534, 536 that are biased towards one another tocompress the reservoir 532 towards a relatively low volumeconfiguration. The plates 534, 536 are biased towards one another by oneor more compression bands 538. The pressure storage component 530 canhave a single fluid port 520 to be fluidly coupled to a pressureconditioning apparatus as a side branch. In some embodiments, a pressurestorage component 530 can further comprise a second port such that thereservoir 532 can comprise an inlet port and an outlet port.

With reference to FIG. 16, the illustrated pressure storage component630 can comprise a reservoir 632 that is housed within a housing orcanister 612. A compression plate 636 can bear on a wall of thereservoir 632 to compress the reservoir against an inner wall of thecanister 612. The compression plate 636 can be coupled to the canister612 by a coil spring 638. A position of the compression plate 636relative to the housing, and therefore a biasing force generatedthereby, can be adjusted by an adjustment mechanism such as a threadedshaft 640. In some embodiments, the pressure storage component 630 canbe configured with an inlet port 620 and outlet port 660 for fluidcoupling in a pressure conditioning apparatus in series.

With reference to FIG. 17, a side view of another embodiment of gas flowpressure conditioning apparatus is illustrated. The apparatus of FIG. 17is substantially similar to that of FIG. 13, with no housing containingthe pressure storage component 430 and accumulator 450. A gas flowconduit 470 can fluidly couple the pressure storage component 430 andaccumulator 450 to an inlet port 420 and outlet port 460 that is coupledto a simulated body conduit 180. The pressure storage component 430comprises a polymeric film pouch that is compressed by an expandablemesh as further described with reference to FIG. 14.

With reference to FIGS. 18A-18D, various embodiments of flow restrictor750, 760, 770 for use with the pressure conditioning apparatusesdescribed herein are schematically illustrated. As noted above withrespect to FIGS. 7-9, in some embodiments, a flow restrictor can beserially coupled in a pressure conditioning apparatus between a pressurestorage component and an apparatus. Many insufflation pumps providepulsing output having pressure pulses defined by an amplitude and aduration. One or more flow restrictors positioned in series within a gasconduit 740 or tube (FIG. 18B) or as a side branch (FIGS. 18C, 18D) cancondition the pulsing output to reduce the amplitude and lengthen theduration of the pulses downstream of the flow restrictor. Accordingly,the pressure conditioning apparatuses described herein can comprise aflow restrictor to further condition the gas flow therethrough tomaintain substantially constant pressure at an outlet of the apparatusdespite a pulsed inflow. In some embodiments, the flow restrictor 750comprises flow restrictor plate 750 with a relatively small diameterorifice 755 positioned in a relatively large diameter gas conduit ortube 745. (FIG. 18B). In other embodiments, the flow restrictor 760comprises a side branch attenuator having a canister or tube 762 havinga restrictor plate 765 therein with a relatively small diameter orifice.(FIG. 18C). The side branch attenuator tube 762 is fluidly coupled on aside branch of a flow conduit. In other embodiments, the flow restrictor770 can comprise a Helmholz resonator comprising a plurality ofrestrictor plates 774 with relatively small diameter orifices positionedwithin a tube 772 or canister fluidly coupled on a side branch of a flowconduit.

With reference to FIGS. 19A-19F it is contemplated that in variousembodiments, the pressure conditioning apparatuses 810 described hereincan be fluidly coupled to an insufflation pump 800 and fluidly coupledto an open-ended body conduit such as a patient's rectum 820 to define asurgical system configured to maintain a desired insufflation pressureprofile. While FIGS. 19A-19F label the pressure conditioning apparatuses810 as ‘BAG’, it is contemplated that the embodiments of surgical systemschematically illustrated therein can incorporate the pouch-basedpressure conditioning apparatus described with respect to FIGS. 1-4, anyof the various other embodiments of pressure conditioning apparatusdescribed herein, or another pressure conditioning apparatusesconfigured to maintain a desired insufflation pressure profile.

With reference to FIG. 19A, the illustrated embodiment of surgicalsystem comprises a pressure conditioning apparatus 810 fluidly coupledto an insufflation pump 800 by a first fluid coupling 830 and fluidlycoupled to a body conduit by a second fluid coupling 840. Arrowheadsschematically illustrate a direction of fluid flow within the surgicalsystem. In some embodiments, the first fluid coupling 830 and the secondfluid coupling 840 can each comprise a segment of gas flow tubing suchas are illustrated in FIG. 4. In some embodiments, the second fluidcoupling 840 can be coupled to the body conduit at an insufflation portof a surgical access port such as a cannula or directly through anartificial body wall defined by a gel surface of a surgical access portsold under the trademarks GELPORT and GELPOINT.

With continued reference to FIG. 19A, in operation, the serial fluidcoupling of the pressure conditioning apparatus 810 to the body conduitprovided by the first fluid coupling 830 and second fluid coupling 840of the surgical system result in mitigated pulsing or billowing of thebody conduit despite pulsatile operation of the insufflation pump 800.The illustrated surgical system also generates a relatively lowerpressure at the body conduit as compared with an insufflation pumpdirectly coupled to a body conduit. This relatively low pressure resultsfrom the insufflation pump 800 sensing back pressure of the pressureconditioning apparatus 810 at the first fluid coupling 830. Typically,insufflation pumps 800 are configured to provide a pulsed insufflationprofile responsive to pressure variations at a directly-coupled surgicalsite. However, the system volume added by the pressure conditioningapparatus 810 serially fluidly coupled to the body conduit and theinsufflation pump 800 cause the insufflation pump 800 to generate apulsatile pressure flow response to pressure variations at the firstfluid coupling 830 of the system, which may differ from pressure at thebody conduit.

With reference to FIGS. 19B-19F, in various embodiments of surgicalsystem, it can be desirable to reduce the pressure loss at a bodyconduit that tends to result from a serially-coupled pressureconditioning apparatus 810. With reference to FIG. 19B, the illustratedembodiment of surgical system comprises a pressure conditioningapparatus 810 fluidly coupled to an insufflation pump 800 by a firstfluid coupling 830 and fluidly coupled to a body conduit by a secondfluid coupling 842. The second fluid coupling 842 can have a thickercross sectional profile defined by a relatively large inner diametercompared to standard insufflation tubing, which typically has a 0.25inch inner diameter. This relatively large inner diameter of the secondfluid coupling 842 increases the flow rate of insufflation gas from thepressure conditioning apparatus 810 to the body conduit, maintaining arelatively higher pressure in the body conduit than that of theembodiment of FIG. 19A.

With reference to FIG. 19C, the illustrated embodiment of surgicalsystem comprises a pressure conditioning apparatus 810 fluidly coupledto an insufflation pump 800 by a first fluid coupling 830 and fluidlycoupled to a body conduit by a second fluid coupling 840. The firstfluid coupling 830 can comprise a flow splitter such as a y-junction ory-valve to provide a dual lumen insufflation gas delivery pathway havinga third fluid conduit 834 providing a parallel fluid flow path from theinsufflation pump 800 to the body conduit. This dual lumen insufflationgas delivery pathway increases the flow rate of insufflation gas fromthe insufflation pump 800 to the body conduit, maintaining a relativelyhigher pressure in the body conduit than that of the embodiment of FIG.19A.

With reference to FIG. 19D, the illustrated embodiment of surgicalsystem comprises a pressure conditioning apparatus 810 fluidly coupledto an insufflation pump 800 by a first fluid coupling 830 and fluidlycoupled to a body conduit by a second fluid coupling 840. The firstfluid coupling 830 can comprise a one-way valve 836 coupled to aparallel return lumen 838 that is fluidly coupled to the body conduit.This one-way valve 836 and return lumen 838 configuration providesbackpressure feedback to the insufflation pump 800 while an insufflationgas delivery pathway is provided from the insufflation pump 800 throughthe pressure conditioning apparatus 810 to the body conduit, thusmaintaining a relatively higher pressure in the body conduit than thatof the embodiment of FIG. 19A.

With reference to FIG. 19E, the illustrated embodiment of surgicalsystem comprises a pressure conditioning apparatus 810 fluidly coupledto an insufflation pump 800 by a first fluid coupling 830 and fluidlycoupled to a body conduit by a second fluid coupling 840. The surgicalsystem further comprises a suction device 860 fluidly coupled to thebody conduit by a first return conduit 862 and to the pressureconditioning apparatus 810 by a second return conduit 864, defining aninsufflation gas return pathway. Thus, insufflation gas drawn out of thebody conduit is reintroduced to the body conduit by way of the pressureconditioning apparatus 810. The gas return pathway can further comprisean in-line filter to prevent hazardous materials from re-entering thebody conduit. This suction device 860 and return pathway can compensatefor insufflation gas loss thus maintaining a desired pressure in thebody conduit.

With reference to FIG. 19F, the illustrated embodiment of surgicalsystem comprises a pressure conditioning apparatus 810 fluidly coupledto an insufflation pump 800 by a first fluid coupling 830 and fluidlycoupled to a body conduit by a second fluid coupling 840. The surgicalsystem further comprises a suction device 860 fluidly coupled to thebody conduit by a first return conduit 866 and a reintroducing conduit868, defining an insufflation gas return pathway that directly returnsinsufflation gas to the body conduit. Thus, insufflation gas drawn outof the body conduit is reintroduced to the body conduit by way of thereintroducing conduit 868. The gas return pathway can further comprisean in-line filter to prevent hazardous materials from re-entering thebody conduit. This suction device 860 and return pathway can compensatefor insufflation gas loss thus maintaining a desired pressure in thebody conduit.

With reference to FIGS. 20-24, by assessing pressure conditioningperformance over a series of simulated leakage tests including severalembodiments of pressure conditioning apparatus, desirable configurationsof the pressure conditioning apparatus can be identified. With referenceto FIG. 20, baseline results in a test fixture of a simulated leak testincluding a silicone simulated rectum, a GELPOINT Path surgical accesssystem and a standard pulsatile insufflator are illustrated. A pressuresensor was inserted into the simulated rectum to measure the internalpressure of the system. In a control setup, a GELPOINT Path stopcock wasopened approximately half-way to create a leak rate of 10L/min. The leakrate was kept consistent throughout subsequent tests of differentembodiments of pressure conditioning apparatus of FIGS. 21-24. Theinsufflator was set at 15 mmHg, high flow. The insufflator turned onafter 5 seconds.

FIG. 20 illustrates an exemplary observed pressure (in mmHg) at thesimulated surgical site over time (in seconds). As illustrated, in thebaseline or control configuration with no pressure conditioningapparatus, after an initial lag time of over 5 seconds, the baselinepressure plot 950 fluctuated between approximately 6 mmHg andapproximately 25 mmHg, representing a pressure deviation of 19 mmHg.This fluctuation results in undesirable billowing of internal walls ofthe simulated body conduit.

With reference to FIGS. 21-24, various embodiments of pressureconditioning apparatus were incorporated into a simulated surgical siteaccess system for comparison with the baseline or control pressure plot.With reference to FIG. 21, a pressure plot 960 for a pressureconditioning apparatus including a reservoir having a volume of 3 L isplotted in comparison to the baseline pressure plot 950. As illustrated,the addition of the 3L bag reduced the high to low pressure peak(deviation) to approximately 5 mmHg. With reference to FIG. 22, apressure plot 962 for a pressure conditioning apparatus including areservoir having a volume of 5.5 L is plotted in comparison to thebaseline pressure plot 950. As illustrated, the addition of the 5.5 Lreservoir reduced the pressure deviation to approximately 3 mmHg. Withreference to FIG. 23, a pressure plot 964 for a pressure conditioningapparatus including a reservoir having a volume of 6.7 L is plotted incomparison to the baseline pressure plot 950. The addition of the 6.7 Lreservoir reduced the pressure deviation to approximately 2.5 mmHg. Withreference to FIG. 24, a pressure plot 966 for a pressure conditioningapparatus including a reservoir having a volume of 9 L is plotted incomparison to the baseline pressure plot 950. The addition of the 9 Lreservoir reduced the pressure deviation down to approximately 2 mmHg.

With continued reference to FIGS. 21-24, while an increased reservoirvolume desirably reduced the pressure deviation of the conditionedinsufflation gas flow, the increased reservoir volume also tended toincrease the lag time for the surgical site to achieve a desiredinsufflation pressure. For example, in the embodiments used in thesimulated leakage tests, the observed lag times ranged fromapproximately 12 seconds (FIG. 21) to approximately 30 seconds (FIG.24). Accordingly, in certain embodiments, it can be desirable that thereservoir be sized to provide a relatively low pressure deviation and arelatively low lag time. Moreover, it can be desirable that thereservoir be sized for ease of positioning and use in a surgical workenvironment. Accordingly, in some embodiments, the reservoir can have aninternal volume between 5.5 and 8 liters. More desirably, the reservoircan have an internal volume of at least approximately 6.5 liters. Incertain embodiments, the reservoir can have an internal volume ofapproximately 7.4 liters. Desirably, this range of volumes can provide apressure deviation of under 3 mmHg, a lag time of under 30 seconds, andallow the bag to be positioned relatively easily in a surgical workenvironment.

With reference to FIGS. 25-26, a pressure conditioning profile of asurgical site access system having a pressure conditioning apparatuswith a reservoir having an internal volume of 6.5 liters was furtherverified on a human cadaver. In an experimental surgical access systemsetup, a stopcock on the surgical access port was opened to create a 7L/min leak, the insufflator was set to a flow rate of 9 L/min, andinsufflation pressure was set at 15 mmHg. In a control or baseline test,the rectal pressure fluctuated between 2 mmHg to 9 mmHg (pressuredeviation of 7 mmHg). The control pressure plot 970, representingobserved pressure at the simulated surgical site plotted over time, isillustrated in FIG. 25. The addition of the pressure conditioningapparatus having a reservoir with a volume of 6.5 liters reduced thepressure deviation to approximately 1 mmHg. FIG. 26 illustrates apressure plot 972 for the surgical site access system with the pressureconditioning apparatus.

With reference to FIGS. 27-30, various embodiments of pressureconditioning apparatus having a reservoir with a volume of 6.5 literswere evaluated such that an inner diameter of an outlet tubing or fluidcoupling can be sized and configured to provide a desirable pressureconditioning profile. The experimental setup included a simulated,silicone rectum, a GELPOINT Path surgical access system, a pressureconditioning apparatus having a reservoir such as is schematicallyillustrated in FIG. 2, and a pulsatile insufflator. The reservoir of thepressure conditioning apparatus used was 6.5 L in volume. The outlettubing of the pressure conditioning apparatus was coupled to aninsufflation trocar positioned through the surgical access system. Apressure sensor was inserted into the simulated rectum to measure theinternal pressure of the system. In the control setup, a GELPOINT Pathstopcock was opened approximately half-way to create a leak rate of 10L/min, simulating insufflation gas losses and absorption from an openbody conduit. The leak rate was kept consistent for all of theembodiments of the pressure conditioning apparatus. The insufflator wasset at 15 mmHg, high flow. The insufflator turned on after 5 seconds.Outlet tubing of varying inner diameter sizes were tested, ranging from0.1 inches to 0.5 inches. FIGS. 27-30 illustrate simulated surgical sitepressure conditioning profiles for embodiments of pressure conditioningapparatus having different outlet tubing inner diameters.

With reference to FIG. 27, a pressure plot 990 of a pressureconditioning apparatus having an outlet tubing with an inner diameter of0.1 inches is illustrated in comparison to a baseline pressure plot 980of the setup with no pressure conditioning apparatus. This embodiment ofpressure conditioning apparatus maintained a pressure at the simulatedsurgical site of approximately 9 mmHg. Thus, the resulting pressureconditioning profile has a relatively high pressure drop, defined by thedifference between the set pressure of the insufflator and the observedpressure at the surgical site. However, the pressure conditioningprofile has relatively small pressure deviation.

With reference to FIG. 28, a pressure plot 992 of a pressureconditioning apparatus having an outlet tubing with an inner diameter of0.15 inches is illustrated in comparison to a baseline pressure plot980. As illustrated, the pressure conditioning profile maintains apressure of approximately 13 mmHg, with a pressure deviation ofapproximately 1 mmHg. With reference to FIG. 29, a pressure plot 994 ofa pressure conditioning apparatus having an outlet tubing with an innerdiameter of 0.25 inches is illustrated in comparison to a baselinepressure plot 980. As illustrated, the pressure conditioning profilemaintains a pressure of approximately 14 mmHg, with a pressure deviationof approximately 1.5 mmHg. With reference to FIG. 30, a pressure plot996 of a pressure conditioning apparatus having an outlet tubing with aninner diameter of 0.5 inches is illustrated in comparison to a baselinepressure plot 980. As illustrated, the pressure conditioning profilemaintains a pressure of approximately 14.5 mmHg, with a pressuredeviation of approximately 2 mmHg.

With continued reference to FIGS. 27-30, comparing the pressureconditioning profiles of various embodiments of pressure conditioningapparatus indicates that the smaller the outlet tubing inner diameter,the greater overall colorectal system pressure drop, but the smaller thepressure differential. Correspondingly, a relatively larger tubing innerdiameter tends to yield a pressure conditioning profile with minimizedcolorectal system pressure drop and a relatively larger pressuredifferential.

It can be desirable that the insufflation pressure maintained by thesurgical site access system has a relatively low pressure drop and apressure deviation that is clinically acceptable. Accordingly, in someembodiments, the outlet tubing can have an inner diameter that isdesirably in the range of from approximately 0.25 inches toapproximately 0.5 inches. In certain embodiments, the outlet tubing canhave an inner diameter of approximately 0.5 inches. Advantageously, a0.5 in inner diameter tubing has a relatively small pressure drop and aclinically acceptable pressure differential. In a cadaver lab, apressure differential of 2 mmHg was not visually noticeable. Therefore,the pressure differential caused a 0.5 in inner diameter tubing isacceptable. Insufflation tubing such as the inlet tubing coupling thepressure conditioning apparatus to an insufflation pump can typicallyhave an inner diameter of approximately 0.25 inches. Thus, it isdesirable that the outlet tubing has a larger inner diameter than theinlet tubing. In the embodiment of pressure conditioning apparatushaving an outlet tube with a 0.5 inch inner diameter, the inner diameterof the outlet tubing can be at least twice the inner diameter of theinlet tubing.

In certain other embodiments, it is contemplated that a pressureconditioning apparatus can comprise other mechanical orelectromechanical systems to condition pulsing flow from an insufflationpump to maintain substantially constant pressure at a surgical sitedespite leakage, absorption, and a pulsing input. In some embodiments, asource of compressed air, which may be available for use in a surgicalworkspace, can be used to condition a pulsing gas flow from aninsufflation pump. With reference to FIG. 31, in some embodiments, apressuring conditioning apparatus 1000 comprises an insufflation gasreservoir 1020 with a thin, gas impermeable membrane dividing thereservoir 1020 into an insufflation chamber 1024 and a pressurizationchamber 1026. A compressed air source, such as a compressed air tank1040 can provide air, regulated to a desired pressure by a pressureregulator 1042 to a pressure port 1044 of the pressurization chamber1026. The pressurization chamber 1026 also includes a check valve 1028to maintain a desired pressure within the insufflation chamber 1024 andpressurization chamber 1026.

With continued reference to FIG. 31, in operation, the insufflation pump1010 is fluidly coupled to the insufflation chamber 1024 at an inletport 1015 and fills the insufflation chamber 1024 to capacity withinsufflation gas at a desired pressure. The compressed air tank 1040then pressurizes the pressurization chamber 1026 of the reservoir 1022to a pressure slightly below that desired for the system and lower thanthat required to open the check valve 1028. Reduced backpressure at anoutlet port 1030 of the insufflation chamber 1024 due to gas leakage orabsorption from the surgical site in the system will cause the pressureof the insufflation chamber 1024 to drop if the insufflator 1010 is notcontinuously pressurizing the system. When the insufflator turns off,pressurized air from the pressurization chamber 1026 of the reservoir1020 acts on the flexible membrane 1022 to maintain pressure within theinsufflation chamber 1024 and maintain a substantially continuous supplyof insufflation gas to the patient.

Thus, advantageously, a pressurized two chamber reservoir can prevent alarge pressure fluctuation at a surgical site despite discontinuities ininsufflation gas flow and gas leakage and absorption at the surgicalsite. As the insufflation pump 1010 reengages to increase pressure inthe system, the insufflation gas is pushed into the insufflation chamber1024 of the reservoir 1020 causing the check valve 1028 to open aspressurized air is vented to return the pressurization chamber 1026 to adesired pressure. The cycle of pressurized gas addition to thepressurization chamber 1026 to maintain insufflation gas pressure in theinsufflation chamber 1024 and pressurized gas venting through a checkvalve 1028 as the insufflation chamber 1024 is pressurized by theinsufflation pump 1010 repeats as needed responsive to insufflation gasflow fluctuations and gas leakage and absorption at the surgical site.

With reference to FIG. 32, another embodiment of pressure conditioningapparatus 1100 is schematically illustrated. The apparatus receives aflow of insufflation gas from an insufflation pump 1110, the gas flow ismonitored by a flow sensor 1112, as it passes through an inlet port 1115to an insufflation chamber 1124 of a reservoir 1120. The gas flow exitsthe insufflation chamber 1124 at an outlet port 1130 fluidly coupled toa surgical site. Pressure conditioning can be supplied to the reservoir1120 by a sliding piston or plunger 1122 coupled to a linear actuator1140 with position feedback. A programmable logic controller 1160 canmonitor position data from the linear actuator 1140, pressure data froma surgical site pressure sensor 1114, and gas flow data from the flowsensor 1112 to control the response of the system as a function of theinputs received from the sensors. Electrical coupling of the systemcomponents are illustrated by dashed lines in FIG. 32. The programmablelogic controller 1160 can be electrically coupled to the sensors 1112,1114 and linear actuator 1140 by a wired or wireless connection. A powersupply 1150 is electrically coupled to the programmable logic controller1160 to supply power thereto and can also provide power to the linearactuator 1140.

In use, in conjunction with the insufflation pump 1110 providinginsufflation gas in a discontinuous or pulsed flow profile, the pressureconditioning apparatus 1100 can provide consistent pressurization of asystem despite leakage and/or a pulsing gas flow. In operation, theinsufflation pump 1110 fills the insufflation chamber 1124 of thereservoir 1112 to capacity with insufflation gas at the desiredpressure. The flow sensor 1112 is able to detect when the insufflator isengaged in pressurizing the system and when it is not. Leakage andabsorption in the system at the surgical site will cause the pressure todrop if the insufflation pump 1110 is not continuously pressurizing thesystem. When the insufflation pump 1110 disengages, the flow sensor 1112detects the state of the insufflator and the plunger 1122 is drivenforward by the linear actuator 1140 to maintain a pressure slightlylower than that desired while acquiring constant feedback from thepressure sensor 1114 at the surgical site. Keeping the pressure lowerthan desired will allow the insufflation pump 1110 to detect a leak inthe system prior to the reservoir 1120 fully depleting while minimizingthe fluctuation from insufflation pump 1110 state cycling. When theinsufflation pump 1110 reengages to increase the pressure in the system,the flow sensor 1112 triggers the plunger 1122 to slowly recess,allowing the insufflation chamber 1124 of the reservoir 1120 to refill.The cycle of linear actuator advancement and retreating movement repeatsas needed to maintain a substantially constant pressure at a surgicalsite.

With reference to FIG. 33, another embodiment of pressure conditioningapparatus 1200 is schematically illustrated. The pressure conditioningapparatus 1200 can comprise a reservoir 1220 having a free slidingpiston 1222 disposed therein that divides the reservoir 1220 into aninsufflation chamber 1224 and a pressurization chamber 1226. In otherembodiments, another separation member such as a thin film membrane candivide the reservoir into insufflation and pressurization chambers, asdescribed with respect to FIG. 31 above. An insufflation pump 1210provides gas flow to an inlet port 1215 of the reservoir 1220 through aflow sensor 1212. The flow sensor 1212 is electrically coupled to aprogrammable logic controller 1260 by a wired or wireless connection.The pressurization chamber 1226 of the reservoir 1220 is suppliedcompressed air from a compressed air source such as a compressed airtank 1240 through a pressure regulator 1242. A solenoid valve 1228 thatis electrically coupled to the programmable logic controller 1260 (PLC)can maintain a desired pressure in the pressurization chamber 1226 as afunction of inputs received from the flow sensor 1212. The PLC 1260 canbe powered by a power supply 1250 electrically coupled thereto. In otherembodiments, a check valve can be used instead of the solenoid valve1228, and the apparatus can operate substantially as described withrespect to the embodiment of FIG. 31 without a PLC and flow sensor.

In conjunction with the insufflation pump, the pressure conditioningapparatus 1200 provides consistent pressurization of a system despitepulsing insufflation gas flow and leakage or absorption at a surgicalsite. In operation, the insufflation pump 1210 fills the insufflationchamber 1224 of the reservoir 1220 to capacity with insufflation gas ata desired pressure. The compressed air tank 1240 and pressure regulator1242 then pressurize the pressurization chamber 1226 of the reservoir1220 to a pressure slightly below that desired for the surgical site.The flow sensor 1212 is able to detect when the insufflation pump 1210is engaged in pressurizing the system and when it is not. Leakage andabsorption of insufflation gas from the surgical site will cause thepressure to drop by reducing backpressure at the outlet port 1230 of theinsufflation chamber 1224 if the insufflation pump 1210 is notcontinuously pressurizing the apparatus 1200. When the insufflation pump1210 is not providing a pressure pulse, the compressed air supplied fromthe compressed air tank 1240 to the pressurization chamber 1226 of thereservoir 1220 presses against the piston 1220, sliding the pistontowards the insufflation chamber 1224 to maintain the supply ofinsufflation gas to the surgical site and prevent a large pressurefluctuation from the leak. As the insufflation pump 1210 reengages toincrease pressure, the flow sensor 1212 triggers the PLC 1260 to openthe solenoid valve 1228, allowing insufflation gas supplied to theinsufflation chamber 1224 advance the piston 1222 towards thepressurization chamber 1226. The PLC can close the solenoid valve 1228at a predetermined elapsed time, insufflation flow condition, or someother factor. The cycle of the piston sliding towards the insufflationchamber 1224 then towards the pressurization chamber 1226 repeats asneeded responsive to variations in flow from the insufflation pump 1210and leakage and absorption at the surgical site.

With reference to FIGS. 34A-34C, embodiments of surgical site sealingapparatus for sealing an open ended body conduit are illustrated. Insome TAMIS procedures or other surgical procedures involvinginsufflation of an open-ended body conduit, a sealing apparatus can bepositioned to form a closed, inflatable compartment within theopen-ended conduit. Thus, leakage of insufflation gas from an open endof the conduit can be minimized. Various embodiments of sealingapparatus can be used to minimize billowing of the body conduit in aninsufflation system in conjunction with a pressure conditioningapparatus as described herein. The sealing apparatuses can also reducebillowing of the body conduit when used with an unconditioned pulsinginsufflation pump as gas leakage from an open end of the conduit can bereduced.

With reference to FIG. 34A, a surgical site sealing apparatus cancomprise an elastomeric bag 2100 having an open end 2102 and a closedend 2104 opposite the open end 2102. The elastomeric bag 2100 can besized and configured to be positioned within a body conduit such therectum for a TAMIS procedure. The elastomeric bag 2100 can be inflatablesuch that it has an insertion configuration in which the bag 2100 isadvanceable within the body conduit in an undisturbed state. Theelastomeric bag 2100 can then be inflated to an insufflated condition inwhich the elastomeric bag distends the body conduit. Insufflation gassuch as CO₂ is retained within the elastomeric bag 2100 in the bodyconduit, such as a rectal cavity. Accordingly insufflation pressurelosses due to leakage from a body conduit at a surgical site andabsorption can be minimized. A surgeon can remove a section of theelastomeric bag 2100 to access a wall of the body conduit for surgicaltreatment.

With reference to FIG. 34B another embodiment of surgical site sealingapparatus for sealing an open ended body conduit is illustrated. Asillustrated, the sealing apparatus can comprise an inflatable membersuch as a balloon 2200 or pouch that is fluidly coupled to an inflationfluid supply tube 2202. The inflatable member can have a deflated statein which it is sized to be advanced through an open end of a bodyconduit. Once positioned at a desired location in the body conduit, theinflatable member is inflatable by fluid to an inflated state sized tosealingly engage with walls of the body conduit.

The inflation tube 2202 extends from a proximal end 2204 to a distal end2206 and having a lumen 2208 extending between the proximal end 2204 andthe distal end 2206. The distal end 2206 of the inflation tube 2202 iscoupled to the inflatable member. The lumen 2208 is fluidly coupled tothe inflatable member to provide the fluid to the inflatable member. Theinflation tube 2202 can have a length sufficient to maintain theproximal end 2204 proximal an open end of the body conduit.

In use, the balloon 2200 in the deflated state can be advanced to aposition in a body conduit beyond a desired treatment site, theninflated to sealingly engage with walls of the body conduit and create aclosed volume in the body conduit that includes the treatment site. Asurgical procedure can then be performed at the treatment site. Once thesurgical procedure has been performed, the balloon can be deflated andinflation tube 2202 can be removed from the body conduit by pulling theinflation tube 2202. Thus, the inflation tube 2202 can additionallyfunction as a tether to facilitate removal of the balloon 2200.

With reference to FIG. 34C another embodiment of surgical site sealingapparatus for sealing an open ended body conduit is illustrated. Asillustrated, the sealing apparatus can comprise a flexible diaphragm2300. The sealing apparatus can further comprise a flexible ring 2302disposed around the diaphragm. The flexible ring 2302 can beconfigurable, such as by compressing it, bending, twisting, or rolling,in a first configuration in which the flexible ring 2302 is advanceablethrough the body conduit beyond a treatment site. Once positioned beyondthe treatment site, the bend, twist, or roll of the flexible ring 2302is released, and a bias of the ring 2302 tends to configure the ring ina second configuration in which the flexible ring 2302 is generallycircular such that it is sealingly engageable with a wall of the bodyconduit. In the illustrated embodiment, the flexible ring 2302 canfurther comprise a second, outer ring 2306 coupled to the flexible ring2302 by a plurality of ribs 2304. This double-ring construction canenhance sealing engagement of the ring with a body conduit havingsurface irregularities.

With the ring sealingly engaging the wall of the body conduit, a closedvolume of the body conduit has been created. Thus a surgical treatmentprocedure can be performed at a treatment site within the closed volume.Following the surgical treatment procedure, the sealing apparatus can beremoved.

Although this application discloses certain preferred embodiments andexamples, it will be understood by those skilled in the art that thepresent inventions extend beyond the specifically disclosed embodimentsto other alternative embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Further, the variousfeatures of these inventions can be used alone, or in combination withother features of these inventions other than as expressly describedabove. Thus, it is intended that the scope of the present inventionsherein disclosed should not be limited by the particular disclosedembodiments described above, but should be determined only by a fairreading of the claims which follow.

What is claimed is:
 1. A gas flow pressure conditioning apparatus foruse with a pulsing insufflation pump, the apparatus comprising: an inletport configured to receive a flow of gas from the pulsing insufflationpump; an accumulator fluidly coupled to the inlet port; a pressurestorage vessel fluidly coupled to the inlet port; a flow restrictorfluidly coupled to the inlet port; and an outlet port fluidly coupled tothe inlet port and disposed downstream of the accumulator, the pressurestorage vessel, and the flow restrictor.
 2. The pressure conditioningapparatus of claim 1, wherein the accumulator, the pressure storagevessel, and the flow restrictor are fluidly coupled in series betweenthe inlet port and the outlet port.
 3. The pressure conditioningapparatus of claim 2, wherein the pressure storage vessel is positioneddownstream of the inlet port, the flow restrictor is positioneddownstream of the pressure storage vessel, and the accumulator ispositioned downstream of the flow restrictor.
 4. The pressureconditioning apparatus of claim 1, wherein the pressure storage vesselcomprises a variable volume container biased to a low volume state. 5.The pressure conditioning apparatus of claim 4, wherein the bias of thevariable volume container is selected to return gas flow pressure withina predetermined time.
 6. The pressure conditioning apparatus of claim 1,wherein the accumulator comprises a constant volume container.
 7. Thepressure conditioning apparatus of claim 6, wherein the accumulator hasa volume selected to contain a predetermined proportion of the flow ofgas from the insufflation pump.
 8. The pressure conditioning apparatusof claim 1, further comprising a gas supply tube fluidly coupled to theinlet port and the outlet port and having a first inner diameter, andwherein the flow restrictor comprises a restrictor plate having anorifice within the gas supply tube, the orifice having a second diametersmaller than the first diameter.
 9. The pressure conditioning apparatusof claim 1, wherein the pressure storage vessel comprises a gascontainer having a wall defined by a bellows surface.
 10. The pressureconditioning apparatus of claim 1, wherein the pressure storage vesselcomprises a gas container having a flexible wall and a biasing membercoupled to the flexible wall to apply compression to the flexible wall.11. The pressure conditioning apparatus of claim 10, further comprisinga housing and wherein the pressure storage vessel and the biasing memberare positioned within the housing, the biasing member bearing againstthe housing and the gas container.
 12. An insufflation systemcomprising: a surgical site access port comprising: a port surface; afirst trocar positionable through the port surface, the first trocarhaving a first instrument channel extending therethrough; and a secondtrocar positionable through the port surface, the second trocar having asecond instrument channel extending therethrough and an insufflationport; and a gas flow pressure conditioning apparatus for use with apulsing insufflation pump, the apparatus comprising a reservoircomprising an elastomeric film pouch fluidly couplable to theinsufflation port of the second trocar.
 13. The insufflation system ofclaim 12, wherein the reservoir has a volume of at least 6.5 liters. 14.The insufflation system of claim 12, wherein the surgical site accessport further comprises an access port insufflation port having an innerdiameter.
 15. The insufflation system of claim 14, wherein theinsufflation port of the second trocar has an inner diameter larger thanthe inner diameter of the access port insufflation port.
 16. Theinsufflation system of claim 15, wherein the insufflation port of thesecond trocar has a barbed fitting configured to fluidly couple to thegas flow pressure conditioning apparatus.
 17. The insufflation system ofclaim 16, wherein the gas flow pressure conditioning apparatus furthercomprises an outlet tubing fluidly coupling the elastomeric film pouchto the barbed fitting.